QZS-1 (MICHIBIKI) is the first of three planned satellites to fill coverage gaps from U.S. Global Positioning System satellites caused by signal blockage from mountains and skyscrapers. Developed by the Japan Aerospace Exploration Agency (JAXA) and four government ministries, the Quasi-Zenith Satellite System is aimed at overcoming ground interference by launching more navigation satellites strategically positioned high in the sky above Asia. The line-of-sight navigation signals from GPS satellites can be interrupted in rural hamlets and skyscraper-filled cities like Tokyo, where users occasionally lack sufficient data to determine their position, elevation and time. JAXA says a constellation of three QZSS spacecraft would make three-dimensional navigation coverage available 99.8 percent of the time, an improvement over the estimated 90 percent availability with GPS satellites today. MICHIBIKI will circle the Earth at a 45-degree angle to the equator. Its orbital high point will be more than 24,000 miles (38,600 km) over the northern hemisphere and its lowest altitude will be 20,500 miles (33,000 km), according to JAXA. Projected against Earth's surface, MICHIBIKI's ground track will chart an asymmetric figure-eight pattern stretching from Japan to Australia as it alternates north and south of the equator.